The present invention relates to devices for lifting materials, particularly those used in the building construction trade.
In constructing a house or other building it is necessary to lift many items to or near the top of the building. A prime example is the trusses used to support the roof in a normal individual home. These trusses are generally pre-assembled on the ground or in a factory, raised by one means or another to the top of the house frame and then attached in the appropriate locations. Additional examples are the sheets of plywood often placed on the tops of these trusses to form the basis for the roof and the singles in turn placed on top of the plywood.
In the past, these items have generally been lifted to the housetop by one of three techniques: first, the materials may be lifted by a crane. While a crane can lift the materials farther than any of the other techniques, it has the distinct disadvantage of being very expensive. Second, the materials may be lifted by a forklift. While this technique is much less expensive than using a crane, it still requires the use of a fairly expensive piece of equipment which is designed primarily for moving materials, not lifting them to the tops of buildings. Third, one or more ladders may be placed against the side of the house and the materials manually carried up them. This is unquestionably the least expensive technique, but it also poses the greatest risk of injury to the persons employing it.
It is the purpose of the present invention to provide a device for raising materials to the top of a building which is considerably less expensive than a forklift, while being simultaneously as portable as a ladder and significantly safer.